Method of treating a rollable material to produce sheets or bands having longitudinally decreasing or increasing thickness



June 19, 1945.

METHOD OF TREATING A R P. A. CARLBERG ET AL ,378, OLLABLE MATERIAL TOPRODUCE SHEETS OR BANDS HAVINGLONGITUDINALLY DECREASING OR INCREASINGTHICKNESS Filed Oct. 20, 1942 Patented June 19, 1945 METHOD OF TREATINGA ROLLABLE MATE- RIAL TO PRODUCE SHEETS OR BANDS HAVING LONGITUDINALLYDECREASING OR INCREASING THICKNESS Per Adolf Carlberg, Carl Gustaf Hardaf Segerstad, and Stig Sweden Rye Ryhagen,

Sandviken,

Application October 20, 1942, Serial No. 462,694

In Sweden August 9, 1941 3 Claims.

The present invention relates toa method of rolling strips, sheets androd material tapered in the longitudinal direction.

An object of the invention is to provide an improved method accordin towhich one and the same rolling mill may be used for the rolling ofmaterials having different degrees of taper.

It has been proposed to roll materials having different degrees of taperby rotating the rollers of a rolling mill at a fixed speed whilevertically displacing the adjusting spindles of the mill at a ratechosen'according to the degree of taper required in each particularcase. method necessitates the provision of special control means foradjusting the speed of the motor operating the adjusting spindles.

According to a feature of the present invention, the mutual distancebetween the cooperating rollers of the mill is changed at apredetermined constant rate while the speed of the rollers is adjustedin accordance with the degree of taper required in each particular case.By this method any special control means for the drive of the adjustingspindles may be dispensed with, and the .desired result is obtained byutilizin the existing means for controlling the speed of the rollers.

A cold rolling mill embodying the invention is illustrated by way ofexample in the accompanying drawing. n

I denotes the main drive motor of the rolling mill, 2 a reduction gear,3 a pinion housing, and I the mill frame supporting two rollers 5 and 6.The lower roller 5 is journalled' infixed bearings, while the upperroller 6 is mounted in bearings which may be displaced in the verticaldirection by means of threaded spindles I, 8. The spindles are operatedat a constant rate by a motor 9 through a reduction gear comprisingthe'worm III, the worm-wheel II, the pinion I2 and the spur wheels I3.Thespeed of' the main drive motor I is controlled by an electricalcontrol device 23 which may be operated either by a hand-wheel 24 or bya spur wheel [9 engaging another spur wheel I8 which forms part of adifferential gear I4. Said difierential gear III comprises two solarwheels I5, I 5' and two planet wheels I'I carried by the spur wheel I8.One solar wheel I5 is driven by the motor 9 through a change-speed gear20, and the other solar wheel I6 is driven in the opposite direction bythe main drive motor I through the bevel gears 2|, 22. The describeddiirerential control unit may be put into or out of action by means of aswitch 25 operatingthe This known magnetic clutches 26, 21. The motor 9is controlled by a reversing switch 28.

The setting of the mill unit to a desired degree of taper is obtained byadjusting the speed of the main drive motor I. Said adjustment may beeffected either manually by means of the hand wheel 24 or automaticallyby means of the differential gear unit I4. In the latter case, thechange speed gear 20 is set to a gear ratio correspond ing to thedesired ratio between the speeds of the motors I and 9, and the switch25 is thrown into operative. position, so that the solar wheels I5, I6are driven by the respective motors at speeds determined by the speedsof said motors and by the gear ratios of the gears 20, 2|, 22.

If the speeds of the solar wheels I5, I6 are not equal, the planetwheels I! will rotate around the axis of the differential gear unit,thus producing a rotatory movement of the spur wheels I8 and I9. Themovement of the spur wheel l9 produces a change of the setting of thecontrol device 23 and, consequently, a change of the speed of the motorI. As soon as the speed of the solar wheel I6 is equal to the speed ofthe solar wheel I5 the rotatory movement of the spur wheels I8, I9 willcease.

The construction of the differential gear unit I4 forms no part of thepresent invention, and it is obvious to anyone skilled in the art thatsaid differential gear unit may be replaced by any other known deviceadapted to respond to a difference between the speeds of two axles, andthat various known accessory devices may be used to ensure a smoothcontrol of the speed of the motor I. a

In the operation of the mill unit shown, a blank in the shape of a stripor a sheet may be put several times through the mill, the speed of themain drive motor I during each passage being chosen according to apredetermined program. The screw drive motor 9 may be kept inoperativeduring part of the passage of the material through the mill. Forwell-known reasons it may be nec- 3. In a method recording to claim 2,for the cold rolling of material in which one or more annealingoperations are interposed between successive cold rolling operations,the step of adjusting the speed of the rollers during the rollingoperation subsequent to the last of said annealing operations in such amanner that the percent reduction caused by said rolling operation isequal throughout the length of the blank.

PER ADOLF CARLBERG. CARL GUSTAF HARD AF SEGERSTAD. S'I'IG RYE RYHAGEN.

